From 10585d92da0dc9a18d6392041f909167d6eee566 Mon Sep 17 00:00:00 2001 From: Brian Gaeke Date: Tue, 6 Jul 2004 18:15:39 +0000 Subject: [PATCH] Add helper function. Don't touch GEPs for which DecomposeArrayRef is not going to do anything special (e.g., < 2 indices, or 2 indices and the last one is a constant.) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14647 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp b/lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp index 10482a997c8..bcd0f78aba2 100644 --- a/lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp +++ b/lib/Transforms/Scalar/DecomposeMultiDimRefs.cpp @@ -24,6 +24,7 @@ #include "llvm/BasicBlock.h" #include "llvm/Pass.h" #include "Support/Statistic.h" +#include "Support/Debug.h" using namespace llvm; namespace { @@ -52,6 +53,10 @@ FunctionPass *llvm::createDecomposeMultiDimRefsPass() { return new DecomposePass(); } +static inline bool isZeroConst (Value *V) { + return isa (V) && (cast(V)->isNullValue()); +} + // Function: DecomposeArrayRef() // // For any GetElementPtrInst with 2 or more array and structure indices: @@ -76,8 +81,15 @@ FunctionPass *llvm::createDecomposeMultiDimRefsPass() { // Return value: true if the instruction was replaced; false otherwise. // bool llvm::DecomposeArrayRef(GetElementPtrInst* GEP) { - if (GEP->getNumIndices() < 2) + if (GEP->getNumIndices() < 2 + || (GEP->getNumIndices() == 2 + && isZeroConst(GEP->getOperand(1)) + && isa(GEP->getOperand(2)))) { + DEBUG (std::cerr << "DecomposeArrayRef: Skipping " << *GEP); return false; + } else { + DEBUG (std::cerr << "DecomposeArrayRef: Decomposing " << *GEP); + } BasicBlock *BB = GEP->getParent(); Value *LastPtr = GEP->getPointerOperand(); @@ -90,7 +102,7 @@ bool llvm::DecomposeArrayRef(GetElementPtrInst* GEP) { // If this is the first index and is 0, skip it and move on! if (OI == GEP->idx_begin()) { - if (*OI == ConstantInt::getNullValue((*OI)->getType())) + if (isZeroConst (*OI)) continue; } else // Not the first index: include initial [0] to deref the last ptr